Identification and localization of the nicotinic acetylcholine receptor alpha3 mRNA in the brain of the honeybee, Apis mellifera

The nicotinic acetylcholine receptors are ligand‐gated ion channels responsible for rapid neurotransmission and are target sites for pesticides in insects. In the honeybee Apis mellifera, pharmacological and electrophysiological studies have shown that different nicotinic acetylcholine receptor subtypes may exist in the brain. Here, we have identified a honeybee cDNA that encodes a 537 amino acid protein with features typical of nicotinic acetylcholine receptor α subunit, and sequence homology to human α3. In situ hybridization on cryosections shows that the Apisα3 mRNA is differently expressed in larvae and adult. In larvae, Apisα3 mRNA expression is restricted to the suboesophageal ganglia. In adult, it is further expressed in the optic lobes, the dorsal lobes, the antennal lobes and the calyces of mushroom bodies. Together our results suggest that Apisα3 shows a controlled expression pattern during development.